CN212341403U

CN212341403U - Battery volume change in-situ testing device

Info

Publication number: CN212341403U
Application number: CN202021134637.7U
Authority: CN
Inventors: 徐进; 刘佳; 晏兵; 陈海彬; 陈垦宇
Original assignee: Dongguan Yintian New Energy Co ltd; Dongguan University of Technology
Current assignee: Dongguan Yintian New Energy Co ltd; Dongguan University of Technology
Priority date: 2020-06-18
Filing date: 2020-06-18
Publication date: 2021-01-12
Anticipated expiration: 2030-06-18

Abstract

The invention discloses an in-situ testing device for battery volume change, which comprises a fixed plate and a limiting plate which are oppositely arranged, wherein a cantilever type pressure sensor is arranged on the fixed plate, a tray is arranged on the pressure sensor, a battery testing cavity is formed between the tray and the limiting plate, and a battery to be tested is embedded in the battery testing cavity and is in pressure type tight contact with the tray and the limiting plate. The in-situ test device for the battery volume change has the characteristics of high accuracy, strong real-time property, good consistency and high test efficiency.

Description

Battery volume change in-situ testing device

Technical Field

The invention relates to the technical field of battery testing devices, in particular to a battery volume change in-situ testing device.

Background

The lithium ion battery is called as a rocking chair battery, and lithium ions are inserted into and removed from the positive electrode and the negative electrode in the charging and discharging processes of the battery, so that the volumes of the positive electrode and the negative electrode materials are changed, and the volume of the battery is changed along with the superposition of the volume changes of the unit cells.

The volume change of the battery can be classified into hard swelling and soft swelling in consideration of the intrinsic factor of the volume change. Wherein the hard expansion is mainly volume change of active materials in the battery in the charging and discharging process, and the soft expansion is mainly change caused by side reactions such as gas generation and the like.

The volume change of the battery is generally monitored by a battery in-situ pressure testing device, and the battery in-situ pressure testing device quantifies the change condition of the battery in the charging and discharging process by monitoring the pressure change caused by the volume change of the battery, and accurately detects the volume change condition of the battery in the electrical property testing process.

Chinese patent application CN209085568U discloses a device for testing the volume of a soft package battery, chinese patent application CN108931280A discloses a device and a method for testing the volume of a lithium ion battery, and chinese patent application CN108414043A discloses a device and a method for testing the volume of a soft package lithium ion battery, both of which measure the volume change of soft expansion by the archimedes principle.

Meanwhile, focusing on the hard expansion of the volume change of the active material during the charge and discharge processes has more practical significance for the research of the performance of the lithium ion battery. The volume change of the electrode material of the battery generates larger stress in the battery, thereby generating great influence on the structural layer in the battery, and causing the cycle performance of the battery and even influencing the safety performance parameters of the battery. Therefore, the in-situ test for monitoring the hard expansion volume change during the charging and discharging of the battery has important significance for the performance analysis of the battery.

Moreover, the existing equipment and method for testing the battery volume have high requirements on experimental environment, so that the data are easy to generate large errors. Because the required working conditions required in these testing methods are high, for example, the volume of the ambient gas and the liquid itself is changed due to the temperature change during the testing process, so that the change value is affected, the accuracy of the experiment is directly affected, and the airtightness of the equipment also directly affects the testing result of the equipment. The mode adopting the Archimedes principle is that through the experimental equipment and the method of the battery volume change of backward thrust, the variable and the error caused by the influence of the outside on a substance are difficult to eliminate, the change of the volume can not be well recorded in real time, a data conversion process is needed for obtaining a result, the experiment is difficult to obtain more required data quantity, the obtained data has no good continuity, the experimental process is complicated and long, the efficiency is low, the requirement of an in-situ experiment can not be met, and the application range is greatly reduced.

Disclosure of Invention

The invention aims to provide an in-situ testing device for battery volume change, which has the characteristics of high accuracy, strong real-time property, good consistency and high testing efficiency.

The invention can be realized by the following technical scheme:

the invention discloses an in-situ testing device for battery volume change, which comprises a fixed plate and a limiting plate which are oppositely arranged, wherein a cantilever type pressure sensor is arranged on the fixed plate, a tray is arranged on the pressure sensor, a battery testing cavity is formed between the tray and the limiting plate, and a battery to be tested is embedded in the battery testing cavity and is in pressure type tight contact with the tray and the limiting plate.

Furthermore, deformation reserved areas are arranged between the tray and the cantilever type pressure sensor and between the fixed plate and the cantilever type pressure sensor, when the sensor is influenced by external force, the deformation reserved areas can be deformed, and then the volume change of the battery in the test process is tested.

Furthermore, the fixed plate and the limiting plate are sequentially formed in a clearance mode through the positioning studs in a combined mode, the structure is effectively simplified, and the assembling difficulty is improved.

Furthermore, fixed plate, tray, limiting plate are the rectangular plate, and the locating stud runs through the locating hole that sets up in four right angles departments of fixed plate, limiting plate, has both satisfied most square battery's test needs and has improved its suitability, conveniently adjusts pressure balance again, improves the test accuracy.

Furthermore, the battery to be tested is a soft package lithium ion battery or an aluminum shell lithium ion battery, both are square batteries, the effective contact area with the limiting plate and the tray is large, the volume change induction is sensitive, and the testing accuracy is improved.

Further, the cantilevered pressure sensor is model HH 8628. The method has the characteristics of high precision and strong unbalance loading resistance. Moreover, the sensor is made of high-quality aluminum alloy, the installation is simple and quick, the surface layer electrolytic corrosion prevention treatment is suitable for the force value detection and control of automation equipment and small equipment in a limited space, the sensor is suitable for large-range high-precision metering detection, and the detection precision, sensitivity and automation degree are improved.

Further, fixed plate and limiting plate are corrosion resistant plate, possess better structural stability, avoid its volume change to cause error and influence to the test procedure.

Further, a side portion of the tray is provided with a mounting fixing groove for connecting the cantilever type sensor. This installation fixed slot is the rectangle recess of taking 4 through-holes for can not let the nut protrusion come when connecting the cantilever type sensor through the screw, push up the limiting plate of top, eliminate the test battery and lay with the influence of battery volume test.

The in-situ testing device for the volume change of the battery has the following beneficial effects:

the volume change data is directly quantified through the pressure brought to the cantilever type pressure sensor by the volume change of the battery in the charging and discharging processes of the battery, and the influence of the external environment is reduced, so that the accuracy of the measured data is improved;

secondly, the real-time performance is strong, the volume change of the battery is monitored and recorded in real time through an equipment sensor, secondary transmission and data conversion or backward pushing are not needed, and the real-time performance is strong;

thirdly, the consistency is good, the requirements on the test environment and the test conditions are effectively reduced in the test process, multiple groups of tests can be synchronously performed, and the test consistency is improved;

fourthly, the testing efficiency is high, the testing device can well complete long-time uninterrupted in-situ volume change testing, the testing efficiency is improved, and a large amount of continuous accurate data are brought to the follow-up research on the performance and the volume change of the battery.

Drawings

FIG. 1 is a schematic perspective view of an in-situ testing apparatus for battery volume change according to the present invention;

FIG. 2 is a front view of an in-situ battery volume change testing apparatus according to the present invention;

FIG. 3 is an internal structural view of an in-situ battery volume change testing device according to the present invention;

the reference numbers in the drawings include: 100. a fixing plate; 200. a cantilevered pressure sensor; 300. a tray; 400. a limiting plate; 500. fixing a nut; 600. positioning studs 700, a battery testing cavity 800, a deformation reserved area 900 and a fixing groove.

Detailed Description

In order to make the technical solutions of the present invention better understood by those skilled in the art, the following detailed description of the present invention is provided with reference to the accompanying drawings.

As shown in fig. 1-2, the invention discloses an in-situ testing device for battery volume change, which comprises a fixing plate 100 and a limiting plate 400 which are oppositely arranged, wherein a cantilever type pressure sensor 200 is arranged on the fixing plate 100, a tray 300 is arranged on the pressure sensor 200, a battery testing cavity 700 is formed between the tray 300 and the limiting plate 400, and a battery to be tested is embedded in the battery testing cavity 700 and is simultaneously in pressure type tight contact with the tray 300 and the limiting plate 400.

As shown in fig. 1 to 3, deformation reserved areas 800 are disposed between the tray 300 and the cantilever-type pressure sensor 200, and between the fixing plate 100 and the cantilever-type pressure sensor 200. The fixing plate 100 and the limiting plate 400 are sequentially formed in a clearance mode through the positioning studs 600 in a combined mode, and specifically, the fixing nuts 500 are sleeved at two ends of each positioning stud 600. The fixing plate 100, the tray 300 and the limiting plate 400 are rectangular plates, and the positioning studs 600 penetrate through positioning holes formed in four right-angle positions of the fixing plate 100 and the limiting plate 400. The side of the tray 300 is provided with a mounting fixing groove 900 for connecting the cantilever type sensor 200.

In the invention, the battery to be tested is a soft package lithium ion battery or an aluminum shell lithium ion battery. The cantilevered pressure sensor is model HH 8628. The fixed plate and the limiting plate are both stainless steel plates.

In the present invention, the roles and functions of the different constituent elements are:

limiting plate: use the cuboid structure as the main part, wherein length wide is applicable to most battery structure on the market, and the bending stress to the limiting plate when the battery inflation is also satisfied to the thickness of design. The limiting plate is used for fixing one side face of the battery, and 4 positioning holes are reserved around the limiting plate and used for being matched with the stud nut, so that certain pressure is applied to enable the battery to be fixed between the limiting plate and the tray. When the volume of the battery changes in the charging and discharging processes of the battery, the limiting plate is a fixed surface, and the pressure of the battery changes towards a certain direction.

A tray: the rectangular structure is used as a main body, the size required by the test is met, the mounting fixing groove is reserved on the side face of the cantilever type pressure sensor for eliminating the influence of the fixing screw on the arrangement of the battery, and the tray is connected with the cantilever type pressure sensor through 4 screws and is a pressure-bearing face when the battery changes. The change of volume can exert certain pressure to tray one side in the process of battery charge-discharge, transmits this part's pressure to the sensor through the tray.

Fixing a plate: the cuboid serves as a main structure, the size of the cuboid also meets the test requirement, and 4 positioning holes are reserved on one side of the cuboid and used for being matched with screws to fix the cantilever type pressure sensor. And the limiting plate is matched with the sensor, the tray and the battery to be fixed together.

Positioning a stud: and positioning holes are reserved at the four corners of the limiting plate and the fixed limiting plate for mounting the positioning studs. The locating stud compresses tightly limiting plate, the battery to be measured, tray, cantilever type pressure sensor, fixed limiting plate in proper order through cooperating with the nut, wholly brings certain initial pressure for equipment, presss from both sides the pressure value that changes more accurate when pressing from both sides tight whole messenger battery charge-discharge.

Cantilever type pressure sensor: cantilever beam structure, when the battery takes place the volume change, through the pressure change information that the tray was collected to with real-time data storage and demonstration to control instrument and computer in, with this realization to the pressure real time monitoring of battery volume change

The assembly and use process of the testing device of the invention is as follows:

firstly, two sides of the cantilever type pressure sensor are respectively fixed with the fixing plate and the tray by using screws. The mounting sequence from bottom to top is as follows: the device comprises a fixing plate, a cantilever type pressure sensor, a tray, a battery to be tested and a limiting plate, wherein a positioning stud passes through the limiting plate and positioning holes at four corners of the fixing plate and is fixed by nuts. The nut pretightening force of each position is set to be a uniform numerical value through a torque wrench, so that the pressure of each position of the battery to be tested and the cantilever type pressure sensor is consistent, and the error of pressure change is reduced. The test device is erected during the experiment test, and the pressure change caused by the test device is reduced. After the installation is finished, the device can be started to start to test, in the process of battery charging and discharging, a certain amount of expansion and shrinkage can occur to the volume, the extrusion amount can be caused to the tray, the cantilever type sensor receives the signals and transmits the signals in real time, and the test of an in-situ experiment is finished.

Compared with the prior art, the testing device effectively breaks through the defect that experimental data needs to be recorded step by step in batches due to the limitation of design conditions in the prior art, and overcomes the defects that the testing device does not have the functions of real-time monitoring, real-time recording and real-time result comparison. The testing process of the invention does not need to observe other media as the standard of volume change, so that the tolerance of experimental conditions is obviously improved. When a plurality of groups of experiment tests are transversely compared, the method is favorable for controlling variables brought by experiment conditions and environments, and the measurement has higher accuracy and contrast. Meanwhile, the cantilever type sensor quantifies the volume change of the battery during the charge and discharge performance test into a pressure numerical value, can complete real-time monitoring and recording for a long time uninterruptedly, and provides necessary conditions of in-situ experiments for the battery performance and volume change test.

In practical use, the working temperature range of the device is-5-40 ℃, the nonlinearity, the hysteresis and the repeatability are +/-0.02% of rated output, the safety overload is 120%, the limit overload is 150%, the sensitivity temperature drift and the zero temperature offset are both less than 0.01% f rated output, and the device has high testing precision and sensitivity.

In the description of the present invention, it is to be understood that terms such as "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, which indicate orientations or positional relationships, are used based on the orientations or positional relationships shown in the drawings only for the convenience of describing the present invention and for the simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The above embodiments are only specific embodiments of the present invention, and the description thereof is specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications are possible without departing from the inventive concept, and such obvious alternatives fall within the scope of the invention.

Claims

1. The utility model provides a battery volume change normal position testing arrangement which characterized in that: the testing device comprises a fixing plate and a limiting plate which are oppositely arranged, wherein a cantilever type pressure sensor is arranged on the fixing plate, a tray is arranged on the pressure sensor, a battery testing cavity is formed between the tray and the limiting plate, and a battery to be tested is embedded and arranged in the battery testing cavity and is in pressure type close contact with the tray and the limiting plate.

2. The in-situ battery volume change testing device of claim 1, wherein: deformation reserved areas are arranged between the tray and the cantilever type pressure sensor and between the fixed plate and the cantilever type pressure sensor.

3. The in-situ battery volume change testing device of claim 2, wherein: the fixed plate and the limiting plate are sequentially formed in a clearance mode through the positioning studs in a combined mode.

4. The in-situ battery volume change testing device of claim 3, wherein: the fixed plate, the tray and the limiting plate are rectangular plates, and the positioning studs penetrate through positioning holes formed in four right-angle positions of the fixed plate and the limiting plate.

5. The in-situ battery volume change testing device of claim 4, wherein: the battery to be tested is a soft package lithium ion battery or an aluminum shell lithium ion battery.

6. The in-situ battery volume change testing device of claim 5, wherein: the cantilever type pressure sensor is of type HH 8628.

7. The in-situ battery volume change testing device of claim 6, wherein: the fixed plate and the limiting plate are both stainless steel plates.

8. The in-situ battery volume change testing device of claim 7, wherein: and a side part on the tray is provided with an installation fixing groove for connecting the cantilever type sensor.